Eberhard Deutsch was a New Orleans attorney whose firm had
once employed Jim Garrison. When Garrison, as D.A., was convicted
of criminally libeling the criminal court judges of New Orleans,
Deutsch argued the appeal before the U.S. Supreme court and won a
reversal of the conviction on First Amendment grounds. In 1970,
when some members of Congress were trying to limit Richard
Nixon's military actions in Cambodia, Deutsch was asked to give
an opinion:

New Orleans Times-Picayune June 21, 1970 S1-P5

Local Attorney Submits Report
Deutsch Ideas on Powers Released in D.C.
by Edgar Poe

Washington, D.C. - Historically, Presidents of the United
States, in their constitutional capacity as commanders-in-chief
of our armed forces, have deployed the military without consulting
Congress.

Eberhard P. Deutsch, New Orleans constitutional attorney, in
an 18-page opinion released in Washington Saturday [20th], traced the
constitutional authority he maintains Presidents have pertaining
to deployment of troops in highly sensitive areas.

The Deutsch opinion was delivered to Sen. Gordon L. Alliot of
Colorado, a member of the Republican Policy Committee, who requested
it. Both the Justice Department and the [Nixon] White House have
copies.

The legal commentary grew out of the long-debated proposed amendment
by Sens. John Sherman Cooper, Republican of Kentucky [and WC member],
and Frank Church, Democrat of Idaho, designed to prevent any future
military involvement in Cambodia, or elsewhere, without consent of
Congress.

[...]

[Some excerpts from the Deutsch report:]

"From all the foregoing [historical examples], it should certainly
seem abundantly clear that whenever a state of war exists - whether
declared or undeclared - the President of the United States has, under
the Constitution, as commander-in-chief, full and plenary power to
conduct military operations in prosecution of the war, unhampered
by anything in the nature of strategic legislative restrictions.

"Any other construction of the Constitution would so hamper the
conduct of a war as to portend ultimate military defeat. The
Constitution of the United States was never meant to be construed
as a suicide pact."